The TSA says its officers may ask passengers to turn on devices such as cellphones. It says devices that won't turn on won't be allowed on planes, and those travelers may have to undergo additional screening.
Homeland Security Secretary Jeh Johnson recently ordered the TSA to put extra security measures in place at some international airports with direct flights to the United States.
American intelligence officials have been concerned about new al-Qaida efforts to produce a bomb that would go undetected through airport security.
The TSA will not disclose which airports will be conducting the additional screening.